CONTROL OF DISEASES IN GRAIN.

Shannon News, 15 May 1925, Page 4

CONTROL OF DISEASES IN GRAIN.

EXPERIMENTS AT CENTRAL DEVELr OPMENT FARM. An interesting series of experiments in the control of fungoid diseases in wheat und barley (smut and rust) are at present being conducted at the Central Development Farm, Weraroa, by Mr J. C. Neill, of the Agricultural Department staff. The incidence of these fungoid diseases is now sq general throughout New Zealand that treatment Of the seed before sowing is everywhere recognised as. essential, if a crop is to be reasonably safe from their ravages, the usual method being to soak the seed in a. solution of either formalin or bluegtone. The former is recognised as/the more efficacious—but has the unfortunate effect of reducing the germinating percentage of the corn, and one of the experiments is in the direction of an attempt to discover a means Qf overcoming this dilliculiy. As Mr Neill pointed out to a "Chronicle" representative who visited the Farm yesterday, both smut and rust were fungoid diseases, but whilst the first was controllable by generally recognised treatments, rust had so: far defied all attempts at prevention. Mr Neill stated that he was himself engaged ion experiments (directed towards a controlling agent, and was not without hope of success, but had at present nothing to report. The control of smut, however, was in a totally different category, and experiments' were directed to improved methods rather than to discovery. Two varieties of smut were known, one external, in which the spores clung tq the .outside of the seed—this kind was spread largely by the modern method of threshing in which the spores are flung widely and distributed oyer large quantities of the seed—and the internal, where the disease is actually contained ' within the seed itself. "Both kinds permeated the plant as. it was growing, the former, however, attacking the. flower of the wheat, so. that at this stage balls of smut farmed instead of the flower. The second variety of the disease at- , tacked the grain, so that beneath the shell, the grain instead of being sound, wus a mass of evil-smelling smut. The present difficulty as far as the formalin treatment goes, was that the ; germination returns are reduced 20, 30, and up to 40 per cent., with the result that it was necessary for rar- ■ mers to. sow considerably larger quantities of seed than would be necessary if no treatment were required. He estimated that on an average in New Zealand -one bushel of seed per acre was sowed above the normal required, as an allowance for the loss of fertility sustained in this way. At the same time if there was to be any reasonable guarantee, of a crop, the treatment of seed had to be resorted to. Mr Neill claimed that he had by his. investigations succeeded in improving the formalin process somewhat, but he considered that this form of treatment was out of date as far as results were concerned, its only recommendation being cheapness. He was .at present conducing further investigation work in connection with two German and one American systems, all of which were superior to the old methods. The cost of treatment amounted to about 9d per bushel as against a penny for formalin, but "the germination of the seed, instead of being lowered, was actually improved, returns being as high as 95 per cent., wnilst the growth of the crop was said to be considerably stimulated also. The general use of these methods of prevention, Mr Neill claimed, would greatly reduce the cost Of wheat in New Zealand. If only half a bushel of seed wheat per acre could saved, the cost of sowing the crop would be lowered by at least 3s. 6d per acre, whilst the charge against the crop for the treatment amounted to only, about Is. In all probability the seed saved would be more in the vicinity of a bushel and taken over the whole of New Zealand this saving would amount to a considerable thing. Another disease in Ihe control of which Mr Neill is conducting experiments, is that known as "Take-all" (Ophiobolus Graminus) • which kills out the complete crop in wide patches. The experiments will be carried on during the coming season and should be of wide interest to grain-growers